In a message dated 10/18/02 6:49:31 PM, [log in to unmask] writes:

>"Intake of fiber, beta-carotene, folate, vitamin C and vitamin B6 were
>associated with a lower risk of all four cancer types studied. Use of a
>vitamin C supplement at least once a week for 6 or more months also
>showed a significant association with a lower risk of these cancers."
>
This illustrates a problem with these kinds of retrospective studies --
besides the fact that there are generally overwhelming confounding factors --
is it the food that the people who had cancer ate (at as far as they can
accurately recall) or is a lack of other food in the diet. In this case, did
the people who developed cancer eat meat and milk exclusively with few veggie
or fruits -- so is the correction orientation to this data the negative
correlation with veggies and fruit; or the positive correlation with meat and
milk. I know this thinking is beginning to sink into analyses of diet and
heart disease -- it appears that fat and cholesterol is not harmful, but that
veggies, etc. are protective. Begins to explains some of the anomalous
situations where people eat meat and fat and cholesterol and seemingly escape
high CVD rates -- but they also eat their veggies as it turns out.

> Also, I never find it very useful when something just says a
>risk is "doubled", rather than giving the actual numbers. If the risk
>went from one-in-two-million to one-in-one-million I could live with
>that sort of doubling if there were counter-balancing considerations.
>But if it was one in a thousand to one in five hundred that would be and
>entirely different matter.

Ditto to this -- in fact, in the Cholesterol Myths, Ravnskov reveals how this
kind of statistical chicanery is used to amplify clinically useless results
in heart disease studies.
Namaste, Liz
<A HREF="http://www.csun.edu/~ecm59556/Healthycarb/index.html">
http://www.csun.edu/~ecm59556/Healthycarb/index.html</A>